Concrete mixer



Oct. lO, 1,950 A, G. zlcovlcH 2,525,573

coNcRE'm; MIXER Filed Aug. 50, 1947 3 Sheets-Sheet l A. G. ZICOVICHCONCRETE MIXER Oct. 10, 1950 3 Sheets-Sheet 2 Filed Aug. 30, 1947Arme/vir Oct. 10, 1950 A. G. zlcovlcH 2,525,573

coNcEEEE MIXER Filed Aug. so, 1947 s sheets-sheet s I l1lllnmullulllullllllmmfwii 5 ar M7@ MK- rrae/Yfr Patented ct. l0,

UNITED STATES PATENT `OFFICE Anthony i'iicovioh,` San Jose, Calif.,Aassigx'or of one-half to Arthur W. Caldwell, San Jose,

Calif.

18 Claims. l

This invention relates to concrete mixers and is concerned moreparticularly with such apparatus embodying a non-rotatable mixing tankand means for providing.. an elevated point of discharge for theconcrete.

In the trucking of `concrete mixes from s, central mixing plant totheconstruction job the useiulness of thepug mill concrete mixers embodyinga non-rotatable mixing tank has been limited materially by the lowlevel` of the discharge means and by the difficulty of eiectingdischarge of the complete batch of concrete from the tank. The instantinvention has for its general object the provision of improved concretemixers of the above type which overcome the above-noted dis-` advantagesand which provide for easy discharge of the complete batch of concreteat a desirable high elevation with reference to the` mixer truck as wellas to facilitate loading of either Wet or dry mixtures into the mixingtank and mixing or agitation of the concrete mix while en route from thebatch plant to the construction job.

The above and other objects of the invention will be apparent from thefollowing description of certain preferred embodiments, as illustratedin the accompanying drawings, in which.:

Figure 1 is a side elevational view, partly in section, of a concretemixing truck having a, pug mill mixer thereon embodying the instantinvention, the mixer being shown in section.

Figure 2" is a rear elevation of the mixer.

Figure 3 is a iront elevation of the mixer.

Figure 4 is a transverse sectional View of the mixer taken as indicatedby the line 4 4 in Figure l, the mixing blade being shown in a differentoperative position.

Figure 5 is a fragmentary plan view of the rear end of the mixer.

Referring to Figures l to 4, the mixing truck of the present inventionincludes a truck' chassis I0 having a cab II` and provided with theusual supporting Wheels, only the rear wheels being shown. A stationarymixing tank I2 of the conventional pug mill type is supported on thetruckchassis, and the mixing tank I2 is open at the top in aconventional manner With the top opening being defined by upright angeportions I2a.

Within the tank I2 there is a mixing assembly including a central shaftI3 upon which a spirally arranged mixing and progressing blade I4 ismounted by suitable radial arms I6. Suitable diagonally disposed bracingrods are alsoV provided ior the blade I4. The outer edge or the spiralblade I4 is formed asa resilient extension Ma oi rubber materialrwhicheects a; clean sweep i, a conventional pneumatic cylinder 3i.

around thetwall of the tank while. yielding to permit passage of, rocksin themixture. The resilient blade portion Illa is bolted between ametal support strip I 4bwhich is carried by the support arms I6 andametal clamping strip Ide. The radial dimension.` of the unsupportededge of the resilient portion Maof the mixing blade is coinparable tothelargest diameter of rock in the aggregate employed for the` concrete`mixture. The drive for theishaft I3 (Figures l and 4) may be asuitableform of housed chainy and sprocket drive connection including aconnection lII` from the shaft I3 to an idler` shaft I8, a driveconnection I9 from the idler` shaft I8 toa second idler shaft 2B, and a`drive connection 2l from the idler shaft ZI! to a drive shaft 22. Thedrive shaft 22 is driven through a suitable clutch mechanism 23 from` apower take-off shaft 24 extending to the` conventional trucktransmissionWhich has the usual gear shift lever associated therewith. A clutchcontrol linkage 25 extends from the clutch 23 to the cabfI I.

` An elevated discharge of the concrete mix is provided` at the `rear ofthe mixer, and preferably closely adjacent aside thereof to provide foriiexibility in the point of discharge of the miX either rearwardly or tothe side of the mixer. The rear wall "261 ofthe mixeris providedwith arearwardly oisetportion: 26a providing an :arcuate discharge panfssagedisposed out of the path of the blade. In its lower portionthe dischargepassage has a discharge opening leading. to a discharge ramp 21. Agate2'8is pivoted on the wall portion 26a at 2B and has pivoted theretothe plunger of The cylinder 3|` ispivotally supported at 32 in spacedbrackets 33 and is operable to move the gate 28 of the chute 3Ii issupported by a chain 4-I whose upper end has a vertical pivotal mountingat l2V in verticalv alignmentJ with the pivoted support 39 of thedischarge chute. i

The blade structure. of the inventionhas in additionto the spiral mixingblade I4, a plurality of lifting or discharga blades 46, and as` shown,two opposite lifting blades 46 are provided which-` are helically shapedtocorrespond to the mixing` blade I4. The blades 46 are also mounted onthe shaft I3 by suitable radial arms IS, and each blade d6 includes ametal body portion 46c having bolted thereto a, resilient radial or sideedge portion liib, and a resilient end portion or strip c. One of thelifting blades 4% is mounted with the mixing blade Illa, so that theresilient edge portion lila thereof serves also as the edge 46D of thelifting blade. Referring to Figure 4, it will be noted that the wide endof va blade 46 is of a width corresponding to the width of the recessedor offset discharge passage 26a. As seen in Figure 5, the wide end ofthe tapered lifting blade structure, as well as the end of the spiralblade lli, depart from the general curvature of their helical shape andare disposed substantially at right angles to the adjacent end wall ofthe tank.

Referring to Figure 5, it will be noted that the immediate end portionof the spiral mixing blade ifi has a small straight section adjacent theend wall 2t, and this small straight `portion is occupied by the endstrip ctc of the lifting blades. 'Ihis edge portion operates closelyagainst the end wall so that any material picked up by a lifting bladewill be elevated along the end wall until it arrives at the recessed endwall portion 26a. The discharge chamber provided by the wall portion 26aallows for discharge of the material elevated by the lifting blade overapproximately 90 of its travel when it will flow down onto the dischargeramp 2l if the gate 28 is open. When the gate 28 is in its inclinedclosed position, as shown in Figure 1, it covers the inner portion ofthe discharge ramp 2l and diverts the material back into the tank.

As previously explained, the drive for the mixing and progressing bladeill and for the lifting blades il@ provides for counterclockwiserotation thereof, as viewed in Figure 4, so that the material isprogressed by the blade toward the rearward end of the tank intocooperation with the lifting blades for elevation thereby to thedischarge opening. The side edges of each lifting blade engage both theadjacent end and side walls to lift the material up the corner formedtherey between. the lifting blade structure and its shaping to conformto the spiral of the mixing and progressing blade places the blade inan-inclined position relative to the end'wall 28 and the adjacent sidewall. In this way concrete is pocketed between a lifting blade and thetank walls for elevation to the discharge opening. The resilient edgeIlia of the progressing blade provides for a clean sweep around the wallof the tank so that substantially all of the material will be progressedto the discharge Zone through which the blades 116 travel. At the sametime the resilient edge Ma will yield if a stone does become lodgedbetween it and the wall of the tank so that no jamming will occur. Thefront wall of the tank is engaged by a radial blade i3 which extendsbetween the shaft and the blade Ui, and which is constructed similarlyto the blade le to provide a resilient edge portion. It will be notedthat the wiping action of the resilient blades M, i3 and 46 clean therespective walls of the tank during each rotation thereof.

While I have shown and described certain preferred embodiments vof theinvention, it is apparent that the invention is capable of variation andmodification from the` forms shown so that its scope should be limitedonly by the scope of the claims appended hereto.

f I claim: Y 1 In a concrete mixer, a frame, a stationary It will benoted that the mounting of mixing tank on Said frame having a dischargeopening at an elevated position in an end wall thereof, means providinga recessed discharge passage offset with respect to said wall andextending upwardly from the bottom of said discharge opening, meansdisposed within the tank for progressing concrete therein toward saidend wall, and a concrete elevating blade travelling through said tankadjacent said end wall and a contiguous side wall portion for picking upand carrying concrete to the recessed and offset discharge passage, saidblade including detachable rubber edge portions for operation closelyagainst the tank walls to thereby elevate substantially all of thepick-up concrete ingredients to said discharge opening without effectingappreciable separation of said ingredients.

2. In a concrete mixer, a frame, a stationary mixing tank on said framehaving a discharge opening at an elevated position in a wall thereofadjacent the rear of the frame, a recessed discharge passage formed insaid wall and extending upwardly from said discharge opening, meansdisposed within the tank for progressing concrete therein toward saidwall, and concrete elevating means travelling through said tank adjacentsaid wall for picking up and carrying concrete to the discharge opening,said elevating means extending in the direction of progressing ofconcrete through said tank and being mounted to operate closely againstthe interior of the tank to thereby elevate substantially all of thepickedup concrete ingredients to said discharge opening withouteffecting appreciable separation of the ingredients.

3. In a concrete mixer, a frame, a stationary mixing tank on said framehaving a discharge opening at an elevated position in an end portionthereof, a recessed discharge passage at said end portion of said tankoffset outwardly from said portion and extending upwardly from thebottom `of said discharge opening, means disposed within the tank forprogressing concrete therein toward said end portion and a concreteelevating blade travelling through said tank adjacent said end portionfor picking up and carrying concrete to the discharge opening. li. In aconcrete mixer, a, frame, a stationary mixing tank on said frame havinga discharge opening at an elevated position in an end wall thereof, arecessed discharge passage formed in said end wall and extendingupwardly from said discharge opening, means disposed within the tank forprogressing concrete therein toward said end wall, and a concreteelevating blade travelling through said tank adjacent said end wall anda contiguous side wall portion for picking up and carrying concrete tothe discharge opening, said blade having rubber edge portions foroperation closely against the tank walls to thereby elevatesubstantially all of the picked-up concrete ingredients to saiddischarge opening without effecting appreciable separation of saidingredients.

5. Ina concrete mixer truck of the type for use in transporting andmixing batches of concrete, a stationary mixing tank of generallycylindrical contour having a flanged open top, a spiral mixing andprogressing blade mounted coaxially within the tank and disposed to movematerial toward an end wall thereof having a discharge opening at anelevated position thereon, a discharge ramp extending outwardly fromsaid discharge opening, an offset portion of said wall extendingupwardly from said opening to provide al discharge passage overlying aportion of said ramp, an elevating blade mountednforrotation with saidspiral biadeand disposed `to carry material upwardly to said dischargepassage, and a gate for said opening havinga closed position in which itis positioned to 'deflect material from said discharge `passage backinto said-tank.`

6. In a concrete mixer truck of the type for use in transporting andmixing batches ofconcrete, a stationary mixing tank or generallycylindrical contour having a flanged open top, a spiral mixing andprogressing blade mounted coaxially within the tank and disposed to movematerial toward an end` wall thereof having a discharge opening at anelevated position thereon, a discharge ramp extending outwardly fromsaid discharge opening, an oiisetportion of said Wall extending upwardlyfrom said opening to provide a discharge passage overlying a portion ofsaid ramp, an elevating blade mounted for rotation with said spiralblade and disposed to carry material upwardly to said discharge passage,a gate for said opening pivo-ted at its upper end to said oifset wallportion and having a closed position in which it is positioned todeiiectmaterial from said discharge passage back into said tank, and afluid-actuated cylinder mechanism for operating said gate.

7. In a concrete mixer truck of the type for use in transporting andmixing `batches of concrete, a stationary mixing tank of generallycylindrical contour having a flanged open top, a spiral mixing andprogressing blade mounted coaxially within the tank and disposed to movematerial toward an end wall thereof having a discharge opening at anelevated position therein, a discharged ramp extending outwardly fromsaid discharge opening, an offset portion 'of said wall extendingupwardly from said opening to provide a discharge passage overlying aportion of said ramp, an elevating blade mounted for rotation With saidspiral blade and disposed to travel closely adjacent both the end andside walls of the tank and carry material upwardly to said dischargepassage, and a gate for said opening having a closed position in whichit is positioned to deflect material from said discharge passage backinto said tank.

8. In a concrete mixer, a stationary mixing tank having an elevateddischarge opening and a f concrete elevating zone adjacent thereto, saidzone being defined at least in part by a recessed wall portion of saidtank extending above said discharge opening, a concrete progressor forprogressing the concrete mix into said elevating zone, and elevatingmeans travelling through said zone for picking up and carrying concretemix to the discharge opening.

9. In concrete mixer, a stationary mixing tank having an elevateddischarge opening and a concrete elevating zone adjacent thereto, saidzone being defined at least in part by a recessed wall portion of saidtank, a concrete progressor for progressing the concrete mix into saidelevating zone, and an elevating blade travelling through said Zone forpicking up and carrying concrete mix to the discharge opening and havinga flexible edge portion for operation closely against the tank Wall tothereby elevate substantially all of the picked-up concrete ingredientsto said discharge opening without effecting appreciable separation ofsaid ingredients.

l0. In a concrete mixer, a frame, a stationary mixing tank having anelevated discharge opening and a concrete elevating Zone adjacenttherelli to, said Zone being' dened atleast in part by d recesseddischarge passage adjacent said elevating zoneand being offsetoutwardlytherefrom and extending upwardly from the bottomof said dischargeopening, a concrete progressor for progressing the concrete mix intosaid elevating zone, and anelevating blade travelling through said zonefor picking up and carrying concrete mix to the discharge passage andopening.

l1.` In a concrete mixer, a stationary mixing tank having an elevateddischarge opening at one end thereof and including a recessed` Wallportion positioned above the discharge opening and leading to thedischarge opening, means for elevating material into` said recessed wallportion, and a gate for the opening disposed in its closed position toform a continuation of said wall portion and to thereby re-directmaterial from said recessed wall portion back into the tank.

12. In a concrete mixer, a stationary mixing tank of generallycylindrical contour, spirally arranged mixing and' progressing blademeans mounted for rotation within the tank to move the mixture thereininto a discharge zone, said f blade means including a resilient edgeportion for engaging the tank- Wall, a plurality of elevating devicestravelling through the discharge `zone for lifting the concrete to anelevated point of discharge, said elevating devices extending in thedirection of movement of the mixture through said tank and being mountedto operate closely with respect to the tank interior to thereby lift theconcrete mixture to said point of discharge substantially intact withouteffecting appreciable separation or the ingredients of said mixture, andgate means at said elevated point of discharge.

13. In a concrete mixer of the type for use in transporting and mixingbatches of concrete, a frame, a stationary mixing tank on said framehaving a discharge opening at an elevated position in a wall structureof said tank and adjacent the rear of the frame, means providing arecessed discharge passage offset with respect to said wall structureand extending upwardly from the bottom of said discharge openings, meansdisposed within the tank for progressing concrete towards said wallstructure, and concrete elevating means travelling through said tankadjacent said wall structure and past said discharge opening forelevating concrete along said wall structure to said recessed and offsetdischarge passage.

14. In a concrete mixer of the type for use in transporting and mixingbatches of concrete, a frame, a stationary mixing tank on said framehaving a discharge opening at an elevated position in a wall structureof said tank adjacent a rear corner thereof, means providing a recesseddischarge passage offset with respect to said wall structure andextending upwardly from the bottom of said discharge openings, meansdisposed within the frame for progressing concrete towards said wallstructure, and a concrete elevatin blade mounted in inclined relation tosaid wall structure and for operation close to the interior of said tankwall structure for elevating concrete mixture along said wall structureto said recessed and offset discharge passage without effectingundesirable separation of the ingredients of said mixture.

15. In a concrete mixer of the type for use in transporting and mixingbatches of concrete, a frame, a stationary mixing tank on said framehaving a discharge opening at an elevated position in a, wall structureof said tank and adjacent the rear of the frame, means providing arecessed afi-2am discharge passage offset with respect to said wallstructure and extending upwardly from the bottom of said dischargeopening, means disposed within the tank for progressing concrete mixturetowards said wall structure, and a concrete elevating blade mounted formovement within said tank along a path extending upwardly past saidrecessed and offset discharge passage, said blade bearing an inclinedrelation to said wall structure to form a mixture retaining pockettherewith for elevation of concrete mixture along said path to saiddischarge opening.

16. In a concrete mixer of the type for use in transporting and mixingbatches of concrete, a frame, a stationary mixing tank on said framehaving a discharge opening at an elevated position in a wall structureof said tank and adjacent the rear of the frame, a spiral bladestructure rotatably mounted in said tank for progressing materialtowards said wall structure, an elevating blade carried by said bladestructure adjacent one end thereof and generally shaped to conform tothe spiral of said blade structure and forming with said wall structurea pocket capable of retaining concrete mixture during elevation thereoffor discharging the mixture from the tank.

17. In a concrete mixer of the type for use in transporting and. mixingbatches of concrete, a stationary mixing tank having an elevateddischarge opening adjacent one end thereof and including a recessed wallportion positioned above the discharge opening and leading to thedischarge opening, means for elevating material into said recessed wallportion, and a gate for opening. Y

18. In a concrete mixer of the type for use in transporting and mixingbatches of concrete, a stationary mixing tank of generally cylindricalcontour, a spiral mixing and progressing blade mounted coaxially withinthe tank and disposed to move the material toward a wall structurethereof having a discharge opening at an elevated position thereon, adischarge ramp extending outwardly from said discharge opening, anoffset portion of said wall structure extending upwardly from saidopening t0 provide a discharge passage overlying a portion of said ramp,an elevating blade mounted for rotation with said spiral blade anddisposed. to carry material upwardly to said discharge passage, and agate for said opening.

the

ANTHONY G. ZICOVICH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 21,827 Erickson et al June17, 1941 824,075 Gerner June 19, 1906 891,468 Dougan June 23, 19081,825,261 Burns et al Sept. 29, 1931 1,999,411 Haney Apr. 30, 19352,047,317 Esslen July 14, 1936 2,082,752 Lewis et al. June 1, 1937

